Solid ink or phase change ink imaging devices, hereafter called solid ink printers, encompass various imaging devices, such as printers and multi-function devices. These printers offer many advantages over other types of image generating devices, such as laser and aqueous inkjet imaging devices. Solid ink or phase change ink printers conventionally receive ink in a solid form, either as pellets or as ink sticks. A color printer typically uses four colors of ink (yellow, cyan, magenta, and black).
The solid ink pellets or ink sticks, hereafter referred to as ink, sticks, or ink sticks, are delivered to a melting device, which is typically coupled to an ink loader, for conversion of the solid ink to a liquid. A typical ink loader includes multiple feed channels, one for each color of ink used in the imaging device. Each channel has an insertion opening in which ink sticks of a particular color are placed and then either gravity fed or urged by a conveyor or a spring-loaded pusher along the feed channel. Each feed channel directs the solid ink within the channel towards a melting device located at the end of the channel. Each melting device receives solid ink from the feed channel to which the melting device is connected and heats the solid ink impinging on it to convert the solid ink into liquid ink that is delivered to a print head for jetting onto a recording medium or intermediate transfer surface.
Each feed channel insertion opening may be covered by a key plate having a keyed opening. The keyed openings help ensure a printer user places ink sticks of the correct color in a feed channel. To accomplish this goal, each keyed opening has a unique shape. The ink sticks of the color corresponding to a particular feed channel have a shape corresponding to the shape of the keyed opening. The keyed openings and corresponding ink stick shapes exclude from each ink feed channel ink sticks of all colors except the ink sticks of the proper color for the feed channel.
Although keyed openings are useful for reducing the likelihood that an ink stick of the wrong color is inserted into a feed channel, ink sticks vary in other important aspects. To detect these other varying aspects and block non-compliant sticks from use in a feed channel, other ink stick identifying systems have been developed. These systems use imaging devices, contact, and/or non-contact switches and sensors to identify an ink stick inserted into a feed channel and block the feed channel in response to a non-conforming ink stick being detected. These systems, however, currently require the sensors or switches to be configured for the type of ink stick to be used in a printer at the manufacturing facility. For identification systems, data identifying the ink sticks must be stored in the printer software at the manufacturing site. In order for each printer to be configured properly at a manufacturing facility, the sensing system and/or data must be identified at the factory and installed in the printer. Thus, the intended use or customer of a machine must be known at the time that the printer is built. If completion of a printer at a manufacturing site is required before a customer can obtain a printer, a delay ensues and a potential customer may decide to purchase a more readily available device. Alternatively, establishing an inventory of multiple printers that are predefined and configured differently is impractical.
One approach for addressing this issue would be to install the identifying data in the printer at a user's site using a memory fob or data entry device, such as a keyboard or other user interface. The memory fob or keystroke sequence, however, could be surreptitiously obtained and used to program other printers for temporary use of non-conforming ink sticks. In other words, the identifying system could lose the ability to detect non-conforming ink sticks and alert the user to the potential use of such ink sticks in a printer. Non-conforming ink sticks include various ink formulations, hue and color saturations, as well as different sizes and shapes. Even if non-conforming ink sticks are used in a printer temporarily, the operation of the printheads could be affected and printed image quality degraded. The effect on ink quality may continue after the use of conforming ink sticks is commenced again. A more robust manner of enabling ink stick identification systems in printers would be beneficial.